Spacecraft for communications and broadcast services can operate in orbit to communicate with a user terminal (or ground device) by way of a forward user downlink signal (transmitted by the spacecraft) and a return user uplink signal (transmitted by the user terminal) that communicatively couple the user terminal and the spacecraft. The operational parameters, such as effective isotropically radiated power (Eirp), antenna gain-to-noise temperature (G/T), space-ground relative positioning, antenna pointing, etc., of the forward user downlink signal and the return user uplink signal can drift over time, for example, due to temperature changes on the spacecraft, drifts in orbit, etc.
Beamforming is a technique in which feed array antennas are configured to geographical confined areas, referred as beams, for the forward user downlink signal and the return user uplink signal such that they are optimized in data capacity at a specific location of the user terminal. Beamforming coefficients can be used to adjust the phases and amplitudes of the forward user downlink signal and the user uplink signal at the feed array antenna transmitter and receiver, respectively, to form beams and to correct for drift of the pointing of the signals, and therefore, increase their data capacity.
Digital beamforming (DBF) systems can be used to perform the necessary calculations to perform beamforming. However, the calculations can involve a high number of multiplications and additions, resulting in a large computational load, limiting the applicability of DBF in large-scale systems.
Thus, an improved system for performing the calculations for digital beamforming is desired.